Dielectric waveguide coupling arrangement for use in two-way signaling systems



g- 1962 w. T. WHISTLER 3,048,799

DIELECTRIC WAVEGUIDE COUPLING ARRANGEMENT FOR USE IN TWO-WAY SIGNALING SYSTEMS Filed Oct. 28, 1959 INVENTORI WILLIAM T. WHISTLER,

HIS ATTORNEY.

United States Patent 3,048,799 DIELECTRIC WAVEGUIDE COUPLING ARRANGE- MENT FOR USE IN TWO-WAY SIGNALING SYSTEMS William T. Whistler, Syracuse, N.Y., assignor to General Electric Company, a corporation of New York Filed Oct. 28, 1959, Ser. No. 849,260 2 Claims. (Cl. 33311) This invention relates to wave transmission systems and particularly to coupling arrangements for use in such systems.

It is oftentimes desirable in the wave signaling arts of providing a desired distribution of wave power between a plurality of transmission lines or other transmission media. One common type of such coupling arrangement is the magic tee. For details of the operation of this coupling arrangement, reference should be made to Patent No. 2,445,896, issued July 27, 1948, to W. A. Tyrrell and entitled Dielectric Waveguide Coupling Arrangement for Use in Two-Way Signaling Systems. Unfortunately, this type of coupling arrangement imposes necessary restrictions on the physical orientation of the waveguide components. Where these restrictions cannot be accommodated, resort must be made to other wave coupling arrangements.

It is, therefore, an object of my invention to provide an improved signal processing arrangement.

It is a further object of my invention to provide an improved arrangement for providing sum and difference values of two applied waves.

It is a further object of my invention to provide a simplified magic tee duplexing arrangement.

It is a further object of my invention to provide an improved waveguide configuration for providing sum and difference values of applied signals.

In accordance with one embodiment of my invention an arrangement is provided for deriving sum and difference values of waves available in parallel abutting square waveguides. Briefly, there is provided a first and second waveguide of elongated rectangular cross-section extending in mutually perpendicular first and second directions respectively from a common junction point. The broad walls of the second guide are placed perpendicular to said first direction. The broad walls of the first guide are positioned parallel to said second direction. A rectangular slot for communicating waves between the waveguides is provided in one broad wall of the second guide. In order to couple waves into such arrangement there is provided a pair of parallel spaced apart slots formed on the second bro-ad wall of this second guide and positioned parallel to said second direction. In order to derive the sum and difference values of applied first and second waves, the waves are coupled to respective ones of said slots and utilization means are provided at the exit portions of said first and second guides to yield said sum and difference wave values.

The novel features which I believe to be characteristic of my invention are set forth with particularity in the appended claims. My invention itself, however, both as to its organization and method of operation, together with further objects and advantages thereof, may best be understood by reference to the following description taken in connection with the accompanying drawings in which:

FIG. 1 illustrates prior art magic tee wavegmide configuration used for establishing the background for the present invention; and

FIG. 2 illustrates in combined block diagram and in schematic form an embodiment of the present invention.

Referring to FIG. 1 there is shown a prior art waveguide configuration wherein first waves are applied to an input arm No. 1 of the arrangement and second waves are ice applied to the input arm No. 2'. Depending upon the relative polarizations of the waves applied into the two input arms, sum and difference values of the applied waves are provided at the exit arms shown as 2 and A. If the polarization of the input waves 1 and 2, for example, is changed such that they are similarly polarized, the sum and difference values producing arms are interchanged.

Where the input waves are available in waveguide sections which are closely spaced as, for example, available in two rectangular guides abutting one another, it is obvious that use of the prior art arrangement of FIG. 1 poses some difficulties in that elaborate and expensive coupling circuits are acquired in order to feed the input waves into the wave-guide arms labelled input No. 1 and input No. 2 in FIG. 1.

Referring to FIG. 2 there is shown a source 1 of first waves having, for example, a polarization shown by arrow 2 and a source 3 of second waves having a polarization shown by arrow 4. Assuming the waves are of equal intensity and have identical polarizations as shown by arrows 2 and 4, it is desired to have these two waves add in phase and appear in -a utilization circuit 5 without having any of the waves coupled into the utilization circuit 6. On the other hand if the polarization of the input waves is changed as, for example, shown by dotted arrows 7 and 8, it is desired that the sum value of such waves appear in the utilization circuit 6, whereas the difference value of such waves appear in the utilization circuit 5. It should be noted that the arrangement of FIG. 2 permits the derivation of the sum and difference values without requiring that the sources of the input waves be in spaced-apart waveguides of particular perpendicular orientation with respect to one another.

The manner in which these desired results are accomplished is as follows. Assuming the wave polarizations to be that shown by arrows 2 and 4, then waves from the sources 1 and 3 are propagated through respective waveguide coupling sections which are shown to be of square cross-section. In order to provide a desired value of such, a pair of parallel spaced-apart slots 11 and 12 are provided in the wide face of the rectangular guide 13 which is coupled at one end to the utilization circuit 6. A second rectangular waveguide 14 is provided for coupling waves from the slots 11 and 12 in the utilization circuit 5. It should be noted that the waveguide sections 13 and 14 of rectangular cross-section extend in mutually perpendicular directions from a common junction. The broad wall of section 14 is positioned parallel to the longitudinal direction of the Waveguide section 13, whereas the broad wall of the waveguide section 13 is positioned perpendicular to the longitudinal direction of waveguide section 14. Furthermore, a rectangular slot for communicating waves between wave guides 14 and 13 is provided in the broad wall of the wave guide 13 and is centered on this broad wall of waveguide 13. Waves of the polarization shown by arrows 2 and 4 in passing the slots 11 and 12 are added together and coupled into the waveguide 14 with the polariz ation shown by arrow 15 and thereby coupled into the utilization circuit 5. In passing the slots 11 and 12, waves of the polarization shown by arrows 2 and 4, cancel one another in the waveguide section 13 such that effectively no wave energy is coupled into utilization circuit 6. Of course, the complete cancellation can only take place if the input waves 'are of common polarization and of the same intensity. If they are not, then a residual difference value of the input wave intensity will appear in the utilization circuit 6, whereas a residual sum value of the two input waves will appear in the utilization circuit 5. If the polarization of the input wave is altered to be that shown by the dotted lines 7 and 8, then in passing the waveguide slots 11 and 12 the input waves add in phase in the waveguide section 13, such that a sum value appears in the utilization circuit 6, and the waves subtract from one another and a difference value appears in the utilization circuit 5.

The advantage of the arrangement in FIG. 2 is that sum and difference values of the input waves can be provided in respective ones of the utilization circuits 5 and 6 depending upon the relative polarization of the input waves available from sources 1 and 2. This advantage can be simply realized with structures other than rectangular guides, for example, square guides, circular guides, strip lines, etc. with appropriate coupling.

While a specific embodiment has been shown and described, it will, of course, be understood that various modifications may yet be devised by those skilled in the art which will embody the principles of the invention and found in the true spirit and scope thereof.

What I claim and desire to secure by Letters Patent of the United States is:

1. In combination, in a wave transmission system, a first and a second waveguide of rectangular cross-section extending in mutually perpendicular first and second di rections respectively from a common junction point, the broad walls of said first waveguide being parallel to said second direction, the broad walls of said second waveguide being perpendicular to said first direction, one end of said first Waveguide abutting one broad wall of said second Waveguide, said one broad wall of the second waveguide containing a rectangular opening for coupling waves into said one end of said first waveguide, a pair of parallel spaced-apart slots formed in the other broad wall of said second waveguide and positioned parallel to said second direction, a first square waveguide for propagating Waves of a first polarization, a second square waveguide for the waves from said first and second waveguides with given relative polarizations to respective ones of said slots, means coupled to one of said first and second rectangular waveguides for extracting the sum value of said coupled first and second waves, and means coupled to the other of said first and second rectangular waveguides for extracting the difference value of said first and second waves.

2. In combination, in a wave transmission system, a first and a second waveguide of rectangular cross-section extending in mutually perpendicular first and second directions respectively from a common junction point, the broad walls of said first waveguide being parallel to said second direction, the broad walls of said second waveguide being perpendicular to said first direction, one end of said first Waveguide abutting one broad wall of said second waveguide, said one broad wall of said second Waveguide containing an opening for communicating applied waves to said one end of said first waveguide, a pair of parallel spaced-apart slots formed in the other broad Wall of said second waveguide and positioned parallel to said second direction, first and second square waveguides abutting one another in their longitudinal directions and adapted to propagate first and second applied waves respectively, one end of said third and said fourth waveguide abutting said other broad wall of said second waveguide, means for coupling the waves from said first and second square waveguides with given relative polarizations to respective ones of said slots, means coupled to one of said first and second rectangular waveguides for extracting the sum value of said applied first and second waves, and means coupled to the other of said first and second rectangular waveguides for extracting the difference value of said first and second waves.

References Cited in the file of this patent UNITED STATES PATENTS 2,764,740 Pratt Sept. 25, 1956 2,792,551 Smith May 14, 1957 2,795,763 Tillotson June I l, 1957 2,840,787 Adcock June 24, 1958 2,853,683 Murphy Sept. 23, 1958 FOREIGN PATENTS 747,303 Great Britain Apr. 4, 1956 

